Hello \x0c\xff\xfe \xf7\xcd\x03\x800\xfav
Note that non-ascii characters in the above source code will be escaped (such as \x9f).
Disassemble:
ORG 00000H LD C,B ;0000 48 H LD H,L ;0001 65 E LD L,H ;0002 6C L LD L,H ;0003 6C L LD L,A ;0004 6F O LD A,(BC) ;0005 0A . INC C ;0006 0C . RST 38H ;0007 FF . CP 00AH ;0008 FE 0A . . JR NZ,$-7 ;000A 20 F7 . CALL 08003H ;000C CD 03 80 . . . JR NC,$-4 ;000F 30 FA 0 . HALT ;0011 76 V